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1. WO1995008290 - DISPOSITIF DE VERIFICATION DU CHAMP VISUEL

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

CLAIMS
1. A device for use in the examination of the visual field of a subject, which device comprises a visual target pattern having a plurality of spaced individual fixation targets disposed in a predetermined configuration around a
substantially central test stimulus and across substantially the whole of a visual target pattern, each individual fixatio target incorporating sequence indicating means so as to defin a visually discernible predetermined sequence for fixing of a eye of the subject, in use of the device, on selected
individual fixation targets, the arrangement being such that, in use, actuation of the central test stimulus causes a preselected test stimulus to be presented to the subject unde test.
2. A device as claimed in claim 1 wherein the test stimulus is more visually prominent than the fixation targets when sai test stimulus is constantly exposed.
3. A device as claimed in claim 1 wherein the test stimulus is less visually prominent than the fixation targets when sai test stimulus is presented intermittently.
4. A device as claimed in any one of claims 1 to 3 wherein said test stimulus is a moveable element.
5. A device as claimed in any one of claims 1 to 3 wherein said test stimulus is a light source.
6. A device as claimed in claim 4 wherein said moveable element has a plurality of spaced test stimuli which are different.
7. A device as claimed in claim 4 or claim 6 wherein the moveable element is a rotatable disc.
8. A device as claimed in any preceding claim wherein the test stimuli differs in size, shape, contrast or colour.
9. A device as claimed in claim 8 or 9 wherein the test stimulus is in the form of a spot, wedge or line which change in size as the disc is rotated.
10. A device as claimed in claim 8 or 9 wherein the test stimulus is in the form of a spot, wedge or line which change in contrast as the disc is rotated.
11. A device as claimed in any preceding claim wherein the test stimuli is dark stimuli on a light background or light stimuli on a dark background.
12. A device as claimed in any preceding claim wherein the fixation targets are substantially regularly and arranged in generally spiral configuration around the central test
stimulus .
13. A device as claimed in claim 12 wherein the individual fixation targets are successively arranged.
14. A device as claimed in claim 13 wherein successive targets are adjacent.
15. Apparatus as claimed in any one of claims 1 to 6 wherein the fixation targets are arranged in a distorted spiral pattern in positions which are substantially equi-sensitive with respect of the stimulus.
16. Apparatus as claimed in any preceding claim wherein said visual target has printed thereon a faint grid identifying the various fixation targets in the visual field.
17. A device as claimed in any preceding claim wherein the visual target comprises a hand-held chart having printed thereon about sixty fixation targets identified by sequential numbers.
18. A device as claimed in claim 17 wherein said target numbers are linked by lines for assistance of patients in finding the next number.
19. Apparatus as claimed in claim 17 or claim 18 wherein said sixty fixation targets are located in a substantially central 24 degree field with the facility to test quadrants to 30 degrees .
20. A device as claimed in any one of claims 17 to 19 wherein said target numbers are distributed in a substantially regular fashion at intervals of 4 degrees radially and 30 degrees meridionally.
21. Apparatus as claimed in any preceding claim wherein a plurality of additional targets can be located in the visual field.
22. A device as claimed in claim 21 wherein said additional targets are examinable using a moveable hand-held pointer as a fixation target.
23. A device as claimed in any one of claims 2 to 22 wherein said test stimuli-bearing disc is rotatably attached to the rear of the visual target, said visual target being provided with a central aperture through which the various selected test stimuli on said disc can be viewed by the test subject.

24. A device as claimed in claim 23 wherein the test stimuli are spaced apart in the disc so as to enable a selected stimuli, or a blank space, to be presented to the subject.

25. A device as claimed in claim 23 wherein the test stimuli are positioned close together on the disc to enable one stimulus to be replaced immediately by another stimulus, with a moveable cover being provided to enable the stimuli to be covered up when required by the examiner.
26. A device as claimed in claim 25 wherein the moveable

• cover is in the form of a slidable member which is operable b means of an exposed end extending from the edge of the target chart so as to cover up or reveal each test stimuli.
27. A device as claimed in claim 26 wherein the slidable member is white or opaque or a neutral density filter, the transparency of which varies along its length.
28. A device as claimed in any one of claims 2 to 27 wherein the visual target is a double-sided chart with one side of said chart bearing a target pattern suitable for the right ey and the other side of said chart bearing a target pattern suitable for the left eye, said test stimuli-bearing disc being sandwiched between the two sides of the test chart, and there being a window disposed in the central area of the char through which the various test stimuli on the rotatable disc can be viewed.
29. A device as claimed in any one of claims 2 to 28 wherein a notch is formed in the upper margin of the test chart so as to expose a portion of the disc, the disc being rotatable in either direction by appropriate movement of a finger or other means located at the exposed edge of the disc.
30. A device as claimed in any one of claims 2 to 29 wherein the disc is removably attached to the chart whereby different discs are interchangeable.
31. A device as claimed in any preceding claim wherein the target chart and rotatable disc are formed of a plastics material.
32. A device as claimed in any preceding claim wherein an ey occluder is attached by means of a spiral hinge to a right side-arm which itself is attached by a spiral hinge to a vertical side of the test chart.
33. A device as claimed in any one of claims 1 to 30 wherein an eye occluder is attached to the bottom edge of the chart b means of an arm and a hinge.
34. A method of conducting examination of the visual field o a subject or patient, by examining one eye at a time, using a test chart with a visual target pattern with a plurality of spaced individual fixation targets and test stimulus which ca be selectively presented to the patient/subject, said method comprising the steps of,
positioning the test chart at a desired distance from th subject,
occluding the eye not being examined,
causing the eye under examination to move in a desired sequence between said fixation targets,
presenting a test stimulus to the subject when the eye under test is looking at a selected fixation target,
recording whether the subject has observed said test stimulus, and creating a map of a plurality of such records to allow assessment of said visual field.